Variations in ecosystem functions following shrubs encroachment
Shrub encroachment strengthened ecosystem functioning of the semi-arid alpine steppes, with the mean EMF indexes greatly increased after shrub encroachments (Fig. 4a and Table S3). The BEMF index also significantly increased following the encroachments of both Leguminosae and Non-Leguminosae shrubs (Fig. 4b). However, the BEMF index had neutral trends after shrubs encroachment (Fig. 4c and Table S3). The RII indexes further indicated greater facilitative effects of both Leguminosae and non-Leguminosae shrubs on the EMF and BEMF of the semi-arid alpine steppes (Fig. 4d−e). In pooled all data together, we found that shrub encroachment increased the belowground ecosystem functioning greater than the aboveground ecosystem functioning, with the BEMF and AEMF increased by 295% and 50%, respectively (Fig. 7).